DE19505762A1 - Moulded plastics component - Google Patents

Abstract

The moulded plastics component (22), such as for computers or communications appts. or automatic office equipment, is of a given size with a hollow zone and a shrouding (23) to cover the whole surface area, and give an electromagnetic shrouding action. Also claimed is a mfg. process where a shrouding section (23) is sandwiched between two plastics plates to form a shaped component, which is heated to soften the plastics plates. A compressed gas is fed into a mould, with a recess, shaped to give the moulded plastics component (22) together with a shrouding (23) and a hollow section.

Description

The invention relates to plastic moldings and methods and devices for their manufacture position.

Electronic devices such as computers, communication systems or office equipment Automation now has to be provided with electromagnetic shielding be so that the electromagnetic noise they generate is not emitted to the outside radiates or external electromagnetic noise does not penetrate the devices. If the housing of the device is made of metal, the electromagnetic shielding No problem. If you use housings that are plastic is designed to meet specific weight, cost and requirements To meet appearance, one must take special measures to electromagnetic To achieve shielding.

Are explained in reference to the schematic representations of FIGS. 1A and 1B are known Cover gen with shielding function. Fig. 1A is a plastic door used as a cover for a large data processing unit 11, the electromagnetic shielding specific ensured. On the inner wall made of plastic of a main unit 12 is a conductive body 13 , which consists of a metal plate or a wire mesh, by fastening means 14 , for. B. screws, fixed so that the door forms an elec tromagnetic shield.

Fig. 1B shows the electromagnetic shielding of a relatively small electronic device 15, for. B. a personal computer, with a housing 16 made of plastic. Since the housing 16 is non-conductive, sheet metal parts 17 are arranged in a jacket 18 .

The door shown in Fig. 1A has the disadvantage that because of the attachment of the conductive body 13 to the main unit 12 produced by compression molding, numerous work steps are required for their manufacture.

The construction shown in Fig. 1B has the disadvantage that a large number of parts are required and the manufacturing costs are high because in the housing 18, the parts 17 are arranged.

In order to avoid the effort associated with the conductive body in FIG. 1A and the housing 18 in FIG. 1B, it has already been proposed to bring about the required electromagnetic shielding by applying conductive paint or metallic fillers to the plastic door 11 or the housing 16 to mix in the material from which the door or the housing are made, so that these parts become conductive. However, such a solution has the disadvantage that the recycling of the material becomes difficult and the manufacturing costs are high.

It is therefore an object of the present invention to provide plastic moldings and methods and to specify devices for their manufacture in which the above mentioned parts are eliminated.

Another and more specific object of the invention is to be lightweight and inexpensive producing plastic molding and methods and devices for light and specify inexpensive manufacture of the same.

To achieve these goals, the invention provides a plastic molding, a plastic molded part of predetermined size with a cavity and a shielding part, that extends over the entire surface of a plane in the cavity of the plastic molding extends and causes electromagnetic shielding. The shielding part can be a wire be mesh or braid that ver along its circumference with the plastic molding is bound.

According to another aspect of the invention it is provided that the shielding part on a inner wall of one of the opposite sections of the plastic mold is partially connected with an adhesive. This can prevent that Shielding part in the cavity of the plastic molded part releases.

According to a further aspect of the invention it is provided that at the periphery of the Shielding part, a conductive part emerge from the molded plastic part through an opening can ver that a conductive member with this conductive member via a plug electrically is bound and that on the periphery of one of the opposite sections of the molded plastic part, a conductive connecting member is provided.

According to a further feature of the invention, one of the other is on the periphery opposite sections of the plastic molded part and a conductive member another section of the plastic molding, a projection is provided which the shielding part at the position corresponding to the conductive member against the inner wall of the Plastic molding presses.

According to a further feature of the invention it is provided that in one of the other opposite sections of the plastic molding, a holding groove is formed, in which a conductive member electrically connected to the bottom of the holding groove is arranged,  wherein the holding groove and the inner wall of the other section of the plastic molding forms a sandwich-like layer structure with the shielding part and between the holding groove and the conductive member optionally a conductive insert is arranged.

According to a further aspect of the invention, the holding groove into which the conductive member is used with an interference fit, by forming a projection on the periphery one of the opposite sections of the molded plastic part is obtained, this projection separating the cavity and the holding groove or the like. So that between an air flow can take place in the cavity and the holding groove.

According to another development of the invention, a plug with an interference fit is in the Plastic molding used, in which the shielding part is received, between this plug and the molded plastic part a conductive member is arranged.

According to a further aspect of the invention it is provided that the plastic molding, the has a shielding part, on part of the housing or on the entire housing electronic device, e.g. B. an information processing unit is used, wherein between the shielding part in the plastic molding and the frame of the electronic An electrical connection is made.

The advantage of the plastic molding according to the invention is that its manufacture is easier and cheaper than in the prior art. Other advantages are easy recycling and improvement of the magnetic shielding effect.

The above-mentioned objectives of the invention can also be achieved by a method for the production of a plastic molding, which has the following method steps:
sandwiching a shielding part between two plastic plates to form a molded part,
Heating the molded part to soften the plastic sheets,
Introducing a compressed gas into the molded part, which is arranged in a mold with a recess with a predetermined configuration, so that a plastic molded part is formed, which contains the shielding part and has a hollow cross section. The shielding part can be arranged in a sandwich construction between the two plastic plates, it being attached to one of these plates, if necessary with the aid of a thermosetting adhesive, the plastic plates then being heated by a heating device and thereby softened and in the space between the plates, which are held in the mold, compressed air is introduced so that the plastic molding produced in this way is a part with a hollow cross section.

The advantage of this method is that the production of a molded plastic part is simplified with a shielding part and causes less costs than in the state of the Technology.

The above-mentioned objects of the invention can also be achieved by a method for producing a plastic molding which has the following method steps:
Forming molten plastic into a plate with a cavity and an open end of a given size,
Inserting a shielding part from the open end,
Introducing compressed air into the cavity in a mold with a recess with a predetermined configuration, so that a plastic molded part is formed which contains the shielding part and has a hollow cross section. The advantage of this method is that the production of the plastic molded part with a shielding part is simplified and causes less costs than in the prior art.

The invention further relates to a device which is characterized by
Assembly means for producing a molded part by sandwiching a shielding part between two plastic plates,
Heating means for heating the molded part for softening the plastic sheets and molding means for introducing compressed air into the molded part in a mold which has a recess with a predetermined configuration, so that a plastic molded part is formed which contains the shielding part and has a hollow cross section.

The invention further relates to a device for producing a plastic molding, which is characterized by
Plastic supply means for supplying molten plastic, which is formed into a plate with a cavity and an open end of a predetermined size,
Supply means for supplying a shield member from the open end, and mold means for introducing compressed air into said cavity in a mold having a recess having a predetermined configuration so as to form a plastic molded article containing the shield member and having a hollow cross section.

Further objects and features of the invention will appear from the following detailed Description referring to the accompanying drawings. Show in detail

FIGS. 1A and 1B are schematic diagrams for explaining a known covers with shielding,

Figs. 2A and 2B the structure of a first embodiment of the invention,

Fig. 3 shows the concept 2B is based on the production of the cover unit of Fig. 2A and,

FIGS. 4A to 4D, a method for manufacturing the cover of the first exporting approximately example,

Fig. 5A-5E, another method for preparing the cover unit of the first embodiment,

FIGS. 6A to 6D approximately example a method for producing the cover of a second exporting,

FIGS. 7A and 7B, the structure of the second embodiment,

Fig. 8 is a front view of the plug of FIG. 7A and 7B,

Fig. 9 is a schematic view of the apparatus for manufacturing the cover of FIG. 7A and 7B,

FIG. 10A for the manufacture of the cover of a third example of exporting approximately to 10D, a method

Fig. 11 shows the structure of a fourth embodiment;

Fig. 12 shows the structure of a fifth embodiment,

FIG. 13A and 13B, the structure of a sixth embodiment,

Fig. 14 shows the structure of a seventh embodiment

FIG. 15A and 15B, the structure of an eighth embodiment,

FIG. 16A and 16B, the concept of a mold apparatus for manufacturing the integrated Abdeckein of Fig. 15A and 15B underlies

FIG. 17A to 17D, a method for producing the cover unit of the eighth exporting approximately example,

FIG. 18A and 18B, a modification of the mold apparatus for manufacturing the integrated Abdeckein of the eighth embodiment,

FIG. 19A and 19B are sectional views of the cover unit which is produced by the process of Fig. 18A and 18B

Fig. 20 is an enlarged partial view, showing how the capping of the used ach th embodiment,

Fig. 21 is an enlarged partial view of the holding groove in a different design,

Fig. 22, the construction of a ninth embodiment,

FIG. 23A and 23B, the construction of a tenth embodiment,

FIG. 24A and 24B, an application of the present invention.

In Fig. 2A, 2B and 2C, the construction is shown a first embodiment of the invention. These figures show a cover unit 22 _{A designed} as a molded plastic part, which forms the front of a large information processing unit or the like.

Here, FIG 2A 2B. A rear view, Fig. A front view and Fig. 2C is a sectional view taken along the line AA of Fig. 2A.

The in Figs. 2A to 2C illustrated cover unit 21 _A is a plastics molding of formed hollow cover 22 and a conductive body 23 (shield) which extends over the entire interior (cavity) of the cover 22 includes (details will be described later). The cover 22 has an opening 24 a and optionally a ribbed part 24 b.

Figure 3 shows the concept underlying the manufacture of the cover unit of Figures 2A, 2B and 2C. The molding device 31 _A from FIG. 3, which is used to manufacture the covering unit 21 _A from FIGS . 2A, 2B and 2C, has as the molding means a molding tool 32 , which consists of a movable upper die 32 a and a movable lower die 32 b, that face each other. On the upper die 32 a, an air outlet 33 is formed (through which an air injection part is inserted). The upper die 32 a and the lower die 32 b define a cavity 32 c, which corresponds to the outer contour of the cover. A ribbed part 32 d can also be provided in the molding tool 32 .

Between the upper die 32 a and the lower die 32 b movable heating blocks 35 a and 35 b (heating means) are provided. The distance between them is so large that they can sandwich a molded part 34 .

The device further comprises an assembly and feed device 36 , with the aid of which the molded part 34 can be assembled and transported into the space between the heating blocks 35 a and 35 b. The assembly and feed device 36 assembles the molded part 34 by holding two plastic plates 22 a and 22 b and the conductive body 23 together, using a frame-shaped spacer 37 .

The plates 22 a and 22 b can be made of polyacetal resin, polystyrene, polycarbonate, acrylic, polyethylene, polypropylene, vinyl chloride resin, ABS resin or another material which is suitable for a twin composite process described below. The permissible thickness of the material depends on the degree of softening in a preheating process described below, but should not be more than 8 mm.

The conductive body 23 is used for electromagnetic shielding and is made by molding a conductive material into a thin plate. The conductive body 23 is permeable to air, so that the compressive force of a gas which is introduced during the molding (described below) is supplied to both sides of the thin plate. For the production of the conductive body 23 , for example, the following materials can be used: wires made of copper, aluminum or Monel (an alloy consisting mainly of nickel and copper), which are processed to form a wire mesh, and a nonwoven fabric such. B. an expanded (foamed) metal, or a metal plate with a large number of openings.

The conductive member 23 can also be made of materials other than metal, but the material must be conductive. For example, a conductive plastic into which metal powder or metallic fillers are mixed and which has a large number of openings can be used, or a conductive rubber.

When determining the strength of the conductive body 23 , it must be taken into account whether it is still deformed after the compression molding. If the cover unit 21 to be produced has such a complicated cross section that the conductive body 23 is deformed after molding, a white material is used to produce the conductive body 23 so that it can be easily adapted to the outer contour. This must be taken into account when determining the thickness of the plate forming the conductive body (if a metal plate is used to produce the conductive body) or the wire diameter (if wires are used to form a wire network).

If the conductive body 23 is formed as a plate, its periphery must be processed into separate strips or made porous so that the plastic plates 22 a and 22 b are not prevented from integrally fusing the thin plate (the conductive body 23 ) through one another .

FIGS. 4A, 4B, 4C and 4D illustrate the preparation of the cover unit 21 _A of the first embodiment. In Fig. 4A, the mounting and feeding device 36 holds the plates 22 a and 22 b, the conductive body 23 being sandwiched between them. The spacer 37 is attached to the periphery of the plates 22 a and 22 b to ensure that the interior of the molded part 24 is hermetically sealed. The molded part 34 is then conveyed into the space between the heating blocks 35 a and 35 b and held there.

If the molding 34 is preheated and softened by the heating blocks 35 a and 35 b, who the heating blocks 35 a and 35 b, as shown in Fig. 4B, withdrawn and the upper die 32 a and the lower die 32 b approximated. The temperature of the plates 22 a and 22 b at this stage is, for example, 160-170 ° C (if the molded part 34 has been heated for six minutes).

Then, as shown in Fig. 4C, the upper die 32 a and the lower die 32 b are brought into contact with each other so that the cavity 32 b is ent. From the air outlet 33 from an air injection part 38 , for. B. a hollow needle, inserted into the softened plate 32 a, so that compressed air is forced into the molded part 34 sen. The mold is clamped with a pressure of 25-50 kgf / cm².

The preheated and softened plates 22 a and 22 b are with a pressure (z. B. 3.5 kgf / cm²), which is built up in the cavity 32 c (for 225 seconds) against the inner wall of the mold 32 , ie the wall of the cavity 32 c, pressed. This has the consequence that the plates 22 a and 22 b expand towards the cavity 32 c. The plates 22 a and 22 b are integrally fused together along the edge clamped by the molding tool 32 .

As, FIG. 4D, the outer shape of the hollow molded body thus prepared corresponds to the outer contour of the cavity 32 c. The molded part holds the conductive body 23 in the center of its cross section. The cover unit 21 _{A is obtained} by taking the molded part out of the molding tool 32 and separating its edge parts that are not required.

The shaping device 31 _A from FIGS . 4A to 4D is designed such that the cover unit 21 _{A is produced} in a twin composite process, the hollow body being produced from the two plastic plates 22 a and 22 b. However, it is also possible to produce the hollow body by a blow molding process.

In Figs. 5A to 5E, another method for preparing the cover unit is shown in the first embodiment. Fig. 5A to 5E show the individual Herstellprozeßschritte that are executed by a blow molding apparatus 31 for the _B. This molding device 31 _B comprises the upper die 32 a and the lower die 32 b, the molding tool 32 (molding device), also a blow head 43 (plastic feed device) with a (plastic) feed nozzle 41 for feeding a preform and an air nozzle 42, and one Feed device 44 for introducing the conductive body 23 . In the upper die 32 a and in the lower die 32 b, a vent 46 a and a cooling opening 46 b are provided.

In Fig. 5A molten plastic (the same material from which the plates 22 a and 22 b are made) is fed from the preform feed nozzle 41 of the die 43 , which spreads between the upper punch 32 a and the lower punch 32 b. The pre-form feed nozzle 41 in the blow head 43 ring shape, their dimensions correspond to the size of a molded part. The preform feed nozzle 41 expresses the molten plastic (preform) from a (not shown) printing device with a predetermined pressure.

When the preform 45 expressed by the die 43 hangs a little beyond the lower end of the die 32 , as shown in FIG. 5B, the conductive body 23 is fed from the feeder 44 into the interior of the preform 45 . Then the mold is closed by merging the upper die 32 a and the lower die 32 b. Alternatively, the conductive body 23 can first be introduced by the feed device 44 and then fed to the preform 45 so that it encloses the conductive body 23 . After closing the mold ( Fig. 5C), the air nozzle 42 introduces compressed air so that the preform 45 swells. The air in the cavity 32 c is discharged through the vent 46 a.

The introduction of air caused by the air nozzle 42, the preform 45 c with the cavity wall 32 in fixed contact (5D.) Comes. The preform 45 is then hardened by supplying a coolant through the cooling opening 46 b.

As Fig. 5E shows, the cover unit 21 _{A is completed} by separating the upper die 32 a and the lower die 32 b, removing the air nozzle 42 and separating the unnecessary edge parts.

The blow molding process described above differs from the twin-composite process of Fig. 4A to 4D in that it eliminates the prefabrication of the plates 22 a and 22 b and the molded part 34 . The number of manufacturing steps and the manufacturing time are therefore reduced. The blow molding process can be used not only in the first embodiment, but also in the other embodiments described below.

In the explanation of the following embodiments, those parts are the parts correspond to the first embodiment, provided with the same reference numerals as there and will not be described again.

FIGS. 6A to 6D show the steps for manufacturing the cover of a second embodiment of the present invention. The shape shown in Figure 6C to Fig. 6A tool 32 (the ribbed portion 32 d is omitted) and the heater blocks 35 a and 35 b are the same as in the first embodiment. The assembly and feeder device 36 is also not shown.

In the molding device 31 _A , the molded part 34 which is transported into the space between the heating blocks 35 a and 35 b and held there is prepared in such a way that the assembly and supply device 36 passes the conductive body 23 between the two plates 22 a and 22 b Applying adhesive 47 (adhesive parts) at predetermined locations on the conductive body 23 temporarily. These adhesives are cured when the plates 22 a and 22 b are preheated. Epoxies or phenols are used as adhesives 47 .

The adhesives are cured when the plates 22 a and 22 b are softened by the heat supplied by the heating blocks 35 a and 35 b, so that the conductive body 23 is then fixed, for example, to the plate 22 b.

If the plates 22 a and 22 b are softened, the heating blocks 35 a and 35 b are pulled back, so that, as shown in Fig. 6B, the plate 22 a with the upper die 32 a and the plate 22 b with the lower Form stamp 32 b comes into contact. Then the air injection part 38 presses compressed air into the molded part 34 , so that the heated and softened plates 22 a and 22 b, as shown in Fig. 6C, are pressed against the walls of the cavity 32 c.

As shown in FIG. 6D, the hollow cover unit 21 _A is obtained after the plates 22 a and 22 b have cooled. Since the conductive body 23 is fastened to the inner wall of the cover 21 _A by the adhesives 47 , it is prevented from becoming detached in the molded part 23 .

Since it is assumed here that the conductive body 23 is deformed during molding, it is preferably flexible. For its manufacture, for example, fine metal wires braided into a network or a flexible conductive plastic sheet can be used.

In the second embodiment described above, the conductive body 23 is connected to one of the plates 22 a or 22 b in the preheating process and the plate 22 a is then deformed. Therefore, the conductive body 23 must not oppose the deformation of the plate 22 a, and it should be used for its manufacture, the areas in which the thermosetting adhesives are applied as small as possible and the spaces between them as large as possible.

The cover body 21 thus constructed, in which the conductive body 23 is located inside the cover 22 , acts as an electromagnetic shield and is suitable for use in the large information processing units described below. The manufacturing methods described above, in which the cover 22 and the conductive body 23 are formed simultaneously, are easy to carry out and are inexpensive. Recycling is also easily possible, which further reduces costs.

FIGS. 7A and 7B show the construction of a third embodiment. FIG. 7A is a schematic view and FIG. 7B is a partial cross-sectional view. The hollow cover unit 21 _B shown in FIGS . 7A and 7B consists of the plastic plates 22 a and 22 b (which are also referred to below as the upper cover 22 a and lower cover 22 b).

The cover unit 21 _B includes the cover 22 , which holds the conductive body 23 formed as a wire mesh in its cavity, and a conductive seal 52 (a conductive member) which is fastened with a plug 51 to the periphery of the surface of the upper cover 22 a .

The conductive seal 52 can be made of various flexible and elastic rubber or urethane materials. These include conductive plastic, conductive rubber or plastic, on the surface of which a conductive paint is attached. The conductive seal 52 is placed along the entire periphery of the top cover.

The film-like conductive body 23 has a conductive part 23 a, which emerges from the area in which the upper and lower covers 22 a and 22 b are connected to one another. This conductive part 23 a is guided along the side of the upper cover 22 a so that it is sandwiched between the conductive seal 52 and the upper cover 22 a. The plug 51 clamps the conductive part 23 a together with the conductive seal 52 with the upper cover 22 a.

FIG. 8 shows a top view of the plug 51 from FIG. 7. It is a rivet made of a conductive metal or the like. The plug 51 penetrates the conductive seal 52 , the conductive part 23 a of the conductive body 23 , the upper cover 22 a and the conductive body 23 , so that the conductive seal 52 and the conductive part 23 a are connected together, an electrical contact is made .

Fig. 9 shows a schematic view of a molding device for producing the cover 21 _B of Fig. 7. The molding device 31 _C shown in Fig. 9 differs from the molding device 31 _A of Fig. 3 and Fig. 6A in that the upper Die 32 a₁des molding tool 32 is flat. The other design features are the same. This construction ensures that the molded part 34 , which is formed in the assembly and feed device 36 so that the conductive body 23 as in the case of the first and second embodiments of the two plates 22 a and 22 b and the spacer ter 37 is bordered, closer to the upper die 32 a₁ (ie the plate 22 a).

FIG. 10A to 10D show a method of manufacturing the cover of the third guide From example. In Fig. 10A (not shown in Fig. 10A to 10D) Mon day and feed device 36 transports the molded part 34 into the space between the heating blocks 35 a and 35 b and sets it up there. The molded part 34 is arranged so that the conductive body 23 of the plate 22 a is closer than the plate 22 b. Since the spacer 37 is arranged outside the mold 32 , the spacer 37 prevents air from escaping from the edge region of the mold 32 .

As FIG. 10B shows, the molded part 34 is preheated by the heating blocks 35 a and 35 b (for example to 160-170 ° C.). If the molding 34 is softened, the heating blocks 35 a and 35 b are withdrawn, and the upper die 32 a and the lower die 32 b are moved so that they come into contact with each other.

As shown in FIG. 10C, the cavity 32 c is formed between the upper die 32 a and the lower die 32 b when they are brought into contact with one another. The air injection part 38 consisting of a hollow needle or the like is inserted from the air outlet 33 into the softened plate 22 a, so that compressed air is forced into the molded part 34 . The form closure takes place with a pressure of 25-50 kg / cm².

The plates 22 a and 22 b, which are heated and softened by the preheating, are pressed against the wall of the mold 32 by internal pressure (for example 3.5 kgf / cm 2 (225 seconds)), so that they fit into the cavity 32 c bulge. The two plates 22 a and 22 b are inseparably connected to one another, since their edge regions are fused together by the clamping action of the molding tool 32 .

The outer shape of the cover 21 B corresponds to the outer contour of the cavity 32 c. It has a hollow cross section, the conductive body 23 being closer to the lower end region of the cross section. After removing the cover 21 _B from the molding tool 32 , the edge parts that are not required are cut off. This pruning allows a predetermined length of the conductive body 23 to stand at the periphery. This remaining part is the conductive part 23 a.

If the cover 21 _{B is used} as a cover for a large information processing unit described below, the electromagnetic shielding effect can be improved if the device housing frame with the conductive device 52 is brought into contact so that between the housing frame of the unit and the conductive body 23 is electrically connected. The third embodiment enables easy and inexpensive preparation of the suitable for applications of this type the cover unit _21B.

Fig. 11 shows the construction of a fourth embodiment of the invention. The cover unit 21 _C shown in Fig. 11 is constructed so that the upper cover 22 a and the lower cover 22 b together form the box-shaped hollow cover 22 , with an opening 53 being provided at a predetermined location of the upper cover 22 a which the conductive body 23 is placed on the surface of the upper cover 22 a and clamped together with the conductive seal 52 against the upper cover 22 a.

Fig. 12 shows the construction of a fifth embodiment of the invention. In the cover unit 21 _D shown in FIG. 12, the upper cover 22 a has on its periphery a metal piece 54 with an L-shaped cross section (conductive connecting member) with a vertical leg 54 a which extends over the side wall of the upper cover 22 a , And a horizontal leg 54 b, which extends over the top of the top cover 22 a.

The metal piece 54 consists of a highly conductive metal, e.g. B. copper or aluminum. It is clamped together with the conductive seal 52 , which is held on the horizontal leg 54 b, against the upper cover 22 a. If the metal piece 54 is attached to the upper cover 22 a, it clamps the conductive part 23 a of the conductive body 23 , which emerges from the junction of the upper and lower cover 22 a and 22 b, against the side wall of the upper cover 22 a , so that electrical connection is made between the conductive body 23 and the conductive seal 52 .

The electrical connection between the conductive body 23 and the conductive you device 52 can also be made in that a small length of the conductive part 23 a of the conductive body 23 is guided out of the cover 22 by the conductive part 23 a, the Metal piece 54 and the side of the top cover 22 a formed space is filled with conductive grease and the metal piece 54 is fastened to the side of the top cover 22 a with a screw or the like. Then there is no need for a large length of the conductive part 23 a of the conductive body 23 to be guided out, and the trimming is facilitated.

FIG. 13A and 13B show the construction of a sixth embodiment of the dung OF INVENTION. The cover unit 21 _E shown in FIG. 13A represents a variation which is then particularly suitable in the event that the conductive seal 52 is fastened to the upper cover 22 a with an adhesive. In this embodiment, the lower cover 22 b₁ has a pressure element 55 which is extended in the direction of the underside of the part of the upper cover 22 a in which the conductive seal 52 is fastened with adhesive to the upper cover 22 a. The pressure element 55 presses the conductive body 23 against the underside of the top cover 22 a.

As a result, the conductive seal 52 and the conductive body 23 are close together. The gap that an electromagnetic wave must exceed is only as large as the thickness of the top cover 22 a, so that electromagnetic shielding effect is improved ver.

In Fig. 13B, the conductive gasket 52 is fixed as in the foregoing embodiments, through the plug 51 to the top cover 22 a. By screwing the plug 51 into the pressure element 55 , a firm electrical connection can be made between the conductive seal 52 and the conductive body 23 .

The pressure element 55 can be produced by forming corresponding projections in the lower die 32 b of FIG. 9 at certain intervals.

Fig. 14 shows the construction of a seventh embodiment of the invention. In this embodiment, a seal holding groove 56 is provided along the entire periphery of the upper cover 22 a₁. A conductive part, e.g. B. a metallic insert 57 is integrally formed with the sealing groove 56 . The insert 57 has an H-shaped cross section. The conductive seal 52 is press-fitted into an upwardly open groove 57 a of the insert 57 and fastened there. The bottom wall 56 a of the seal holding groove is very close to the lower cover 22 b and presses the conductive body 23 against it.

Since there is an electrical connection between the conductive seal 52 and the insert 57 and the insert 57 and the conductive body 23 are closely adjacent to each other, the gap which an electromagnetic wave must cross is narrowed, so that electromagnetic shielding effect is improved.

FIG. 15A and 15B show the construction of an eighth embodiment of the invention. FIG. 15A shows the rear view of a cover unit, FIG. 15B a front view and FIG. 15C a cross-sectional view along the line BB of FIG. 15A.

The in Figs. 15A to 15C shown cover unit 21 _G includes the hollow cover 22. A provided at the periphery of the rear of the cover 22 projection 21 a forms a seal-holding groove 61 . The conductive body 23 is disposed inside the hollow cover 22 , and the edge portion of the conductive body 23 extends to the seal holding groove 61 (see FIG. 20).

FIG. 16A and 16B show the concept of a molding apparatus for the manufacture of the cover unit of Fig. 15A and 15B. FIG. 16A is a cross-sectional view showing the concept. Fig. 16B shows a side view of a lower punch 32 b₁. The molding device 31 _D of Fig. 16A and 16B comprises a molding tool 32 , which consists of an upper die 32 a₂ and a lower die 32 b₁ (molding device), which can be approximated and removed from each other.

In the upper die 32 a₂ a recess 62 a is formed. The air outlet 33 is provided in the center and a further air outlet 33 a in the end region of the upper die 32 a₂. In a on the lower die 32 b₁ formed projection 63 a recess 62 b is formed, the flat surface of which is smaller than the flat surface of the recess 62 a of the upper die 32 a₂. The bottom of the recess 32 b is at a higher level than the edge region of the lower die 32 b 1.

If the upper die 32 a₂ and the lower die 32 b₁ are brought into contact with each other, a first cavity 32 c₁ is formed between the recess 62 a and the recess 62 b and between the recess 62 a and the edge of the lower die 32 b₁ a second cavity 32 c₂. The air outlet 33 is in the first cavity 32 c₁ and the air outlet 33 a in the second cavity 32 c₂.

The movable heating blocks 35 a and 35 b are arranged separately from each other between the upper stamp 32 a₂ and the lower stamp 32 b₁. The assembly and feed device 36 for supplying the molded part is arranged between the heating blocks 35 a and 35 b.

FIG. 17A to 17D show the structure of an eighth embodiment. In Fig. 17A, the two plates 22 a and 22 b in the (not shown) Montage and Zufuhrungsvor direction 36 are brought together in a sandwich construction with the conductive body 23 . The molded part 34 , which is hermetically sealed by the spacer 37 provided in the edge region of the plates 22 a and 22 b, is transported into the space between the heating blocks 35 a and 35 b and held there.

If the molded part 34 is pre-heated by the heat generated by the heating blocks 35 a and 35 b, the heating blocks 35 a and 35 b are withdrawn and the upper die 32 a and the lower die 32 b 1 approximate each other. The temperature of the plates 22 a and 22 b is (after a heating time of 6 minutes) for example 160 to 170 ° C.

Subsequently, the upper die 32 a and the lower die 32 b₁, as shown in Fig. 17B, brought into contact with each other so that the first and second cavities 32 c₁ and 32c₂ (first and second spaces) are formed. The Z. B. from a hollow needle air injection part 38 is inserted through the air outlet 33 into the softened plate 22 a, so that air is forced into the molded part 34 . The mold is closed with a pressure of, for example, 25 to 50 kgf / cm².

The heated and softened by the preheating plates 22 a and 22 b are pressed with an internal pressure of, for example, 3.5 kgf / cm² (225 seconds) against the wall of the molding tool, ie against the first and second cavities 32 and 32 c₂ and expanded. The plates 22 a and 22 b are integrally fused together along the edge regions of the first cavity 32 c₁ and the second cavity 32 c₂, while the edge regions are pressed together by the molding tool 32 .

As shows FIG. 17C, the edge portions (the spacer 37 is not shown) by trimming of the molded part 34 separated along the cut line 64.. This ent ent on the back of the cover 22, the seal holding groove 61st

In this seal-holding groove 61 , a conductive seal 65 , which is made of the same material as the conductive seal 52 , is inserted with an interference fit so that it comes into contact with the conductive body 23 . In this way, the manufacture of the cover 21 _G with shielding function is simplified and requires only low costs.

FIG. 18A and 18B show the concept of a variant of the mold apparatus for manufacturing the cover according to the eighth embodiment. Fig. 18A is a cross sectional view and shows the concept, Fig. 18B shows a side view of the lower die 32 b₂ Ren. In the lower die 32 b₂ of the molding device 31 _D of FIGS . 18A and 18B, a certain number of ventilation grooves 63 a are provided in the projection 63 in which the recess 62 b is formed.

Therefore, the upper die 32 a and the lower die 32 b form only a single cavity (the cavity 32 c) when they are brought into contact with each other. This cavity 32 c is ventilated as a whole. In the upper punch 32 a of Fig. 18A, unlike the upper punch 32 a 1 of Fig. 16A and 16B, only a single air outlet 33 may be provided. The other design features are the same as in the embodiment of FIGS. 16A and 16B.

FIG. 19A and 19B show cross-sectional views of the cover with the aid of the forming device 31 _E generated. Fig. 19A is a sectional side view of the cover unit, Fig. 19B is a cross section along the line CC of Fig. 19A. When the cover 21 _H of FIG. 19A and 19B is in the edge region of the lower cover 22 b a predetermined number of projections 61 a formed whose spatial arrangement corresponds to the ventilation grooves 63 a of the B in the lower die 22 provided for the projection 63. The conductive seal 65 is press-fitted into the seal holding groove 61 .

Fig. 20 shows an enlarged partial view of how the cover unit 21 _{H of} the eighth exemplary embodiment is used. Fig. 21 shows a partial enlarged view of another configuration of the seal holding groove.

Fig. 20 shows how the cover 21 _H is attached to an apparatus wherein a frame of the device with the conductive seal 65 electrically connected 71st Since the conductive seal 65 is electrically connected to the conductive body 23 in the seal holding groove 65 , the conductive body 23 and the frame 71 are also electrically connected to each other. As a result, the electromagnetic shielding effect of the conductive body 23 is improved.

Fig. 21 shows a configuration in which the area occupied by the seal holding groove 61 on the upper cover 21 _{H is} kept small, so that a smaller conductive seal 65 a can be used. The upper cover 22 a of the cover unit 22 is bent and forms a slope on the periphery. The projection 61 a of the lower cover 22 b₃ is adapted to the shape of the bent part of the upper cover 22 a.

An electrical connection is made between the conductive body 23 and the frame 71, by bringing the conductive gasket 65 a with the frame 71 in contact, so that an electromagnetic shielding effect is achieved.

Fig. 22 shows the construction of a ninth embodiment of the invention. In the cover unit 21 shown in FIG. 22, the conductive body 23 is located in the hollow cover 22 , a certain number of stoppers 51 in the edge region of the cover 22 being passed through the conductive seal 72 into the lower cover 22 b and the conductive body 23 is driven.

The plug 51 establishes an electrical connection between the conductive body 23 and the conductive seal 72 . The electromagnetic shielding by the conductive body 23 is achieved in that the conductive seal 72 can come into contact with the frame of the device.

FIG. 23A and 23B show the construction of a tenth embodiment of the dung OF INVENTION. FIG. 23A is a cross-sectional view of the cover 21 _K of the tenth exporting approximately example. FIG. 23B shows the cover 21 _K in a partial view from the rear.

In the cover unit 21 _K of FIGS . 23A and 23B, 22 b₄ rows of printing elements, e.g. B. two rows of pressure elements 55 a and 55 b, out. These pressure elements 55 a and 55 b press the conductive body 23 against the upper cover 22 a. An annular opening 72 is formed around the pressure elements 55 a and 55 b of the lower cover 22 b₄.

The conductive seal 52 is press-fitted into the opening 72 so that it is in contact with the conductive body 23 and is electrically connected to it. The conductive seal 52 is exposed from the lower cover 22 b₄ and is brought into contact with the body or frame with which the cover 21 _{K is} assembled, so that electrical connection is established and electromagnetic shielding is achieved.

FIG. 24A and 24B serve to illustrate an application of the invention. Fig. 24A shows a schematic view with parts broken away, Fig. 24B is a plan view showing the internal arrangement.

FIG. 24A and 24B show a large information processing unit 70, in which the covering units are used 21 _A to 21 _K of the preceding embodiments described as a door. On the frame 71 side plates 72 a, 72 b, an upper plate 73 , a bottom plate 74 and the rear wall plate 75 are attached. The cover unit 21 _A ( 21 _B to 21 _K ) is arranged as a door between the side plates 72 a and 72 b.

The electromagnetic shielding effect is ensured by the conductive body 23 of the cover unit 21 _A ( 21 _B to 21 _K ) and the frame 71 . By the electrical connec tion between the frame 71 and the conductive body 23 on the conductive lines 52 and 65 , the electromagnetic shielding effect is improved.

Through the opening 24 a of the cover unit 21 _A ( 21 _B to 21 _K ), a control panel is freely accessible.

FIG. 24A and 24B show the cover units 21 _A to 21 _K according to the present invention applied as a door for a large data processing unit 70. However, they can also be used for the side plates 72 a, 72 b, the upper plate 73 , the bottom plate 74 and the rear wall plate 75 . In addition, the cover units 21 _A to 21 _K can be used not only with large information processing units such as the system 70 but also with devices for office automation, such as copiers, or with electronic devices such as communication systems.

The invention is not limited to the exemplary embodiments presented, there are many more numerous variations and modifications possible, all within the scope of protection Invention lie.

Claims (36)

1. plastic molding, characterized by a plastic molding ( 22 ) of a predetermined size with a cavity and a shielding part ( 23 ) which extends over the entire surface of a plane in the cavity of the plastic molding and causes electromagnetic shielding. 2. Plastic molding according to claim 1, characterized in that the periphery of the shielding part ( 23 ) with the plastic molding ( 22 ) is the verbun. 3. Plastic molding according to claim 1 or 2, characterized in that the shielding part ( 23 ) is connected by an adhesive ( 47 ) to an inner wall of one of the opposite sections of the plastic molding ( 22 ). 4. Plastic molding according to claim 3, characterized in that the adhesive ( 47 ) is a thermosetting agent. 5. Plastic molding according to claim 1, 2 or 3, characterized in that the shielding part ( 23 ) consists of a wire mesh, a metal plate with a predetermined number of holes, a metal foil, a conductive plastic or a conductive synthetic rubber. 6. Plastic molding according to claim 1, characterized in that the edge of the shielding part ( 23 ) is designed so that it emerges from the plastic part ( 22 ) as a conductive part ( 23 a), and that a conductive member ( 52 ) on the circumference one of the opposite sections of the molded plastic part ( 22 ) is electrically connected to this conductive part ( 23 a). 7. plastic molding according to claim 6, characterized in that the conductive part ( 23 a) and the conductive member ( 52 ) are interconnected by a conductive plug ( 51 ). 8. Plastic molding according to claim 6 or 7, characterized in that in the plastic molding ( 22 ) an opening ( 53 ) for the exit of the conductive part ( 23 a) is formed. 9. Plastic molding according to claim 6 or 7, characterized in that the electrical connection between the conductive part ( 23 a) and the conductive member ( 52 ) is made by a conductive connecting member ( 54 ). 10. Plastic molding according to claim 1, characterized in that an elastic conductive member ( 52 ) is provided on the periphery of one of the opposite portions of the plastic molding ( 22 ) and that in the plastic molding ( 22 ) a projection ( 55 ) is formed, which Periphery of the shielding part ( 23 ) at the position corresponding to the conductive member ( 23 ) presses against an inner wall of the plastic molded part ( 22 ). 11. Plastic molding according to claim 10, characterized in that the electrical connection between the conductive member ( 22 or 52 ), the plastic molded part ( 22 ) and the shielding part ( 23 ) is provided by a conductive plug ( 51 ) ago. 12. Plastic molding according to claim 1, characterized in that on one of the opposite sections of the plastic molding ( 23 ) a Hal tenut ( 56 ) is formed and that in this holding groove ( 56 ) an elastic conductive member ( 52 ) is arranged, which with the Bottom of the holding groove ( 56 ) is electrically connected, the holding groove ( 56 ) and the inner wall of the other of the two opposite sections of the molded plastic part ( 22 ) and the shielding part ( 23 ) engaging in a sandwich. 13. Plastic molding according to claim 12, characterized in that in the holding groove ( 56 ) has a conductive insert ( 57 ) for holding the conductive member ( 52 ) and for establishing the electrical connection between the conductive member ( 52 ) and the bottom of the holding groove ( 56 ) is arranged. 14. Plastic molding according to claim 1, characterized in that on the circumference of the plastic molding ( 22 ) by a projection ( 61 a) on the circumference of one of the opposite sections of the plastic molding ( 22 ) and by an end region of the other of the opposite sections of the plastic molding ( 22 ) a holding groove ( 61 ) is formed, into which an elastic conductive member ( 65 ) is press-fitted and that the shielding part ( 23 ) extends to the holding groove ( 61 ). 15. Plastic molding according to claim 14, characterized in that the projection ( 61 a) is arranged such that it separates a cavity in the plastic molding ( 22 ) from the retaining groove ( 61 ). 16. Plastic molding according to claim 14, characterized in that the projection ( 61 a) is shaped such that an air flow between the hollow space of the plastic molding ( 22 ) and the holding groove ( 61 ) is possible. 17. Plastic molding according to claim 1, characterized in that the electrical connection between the plastic molding ( 22 ) and the shielding part ( 23 ) is made by a conductive plug ( 51 ). 18. Plastic molding according to claim 17, characterized in that a conductive member ( 52 ) is arranged between the surface of the plastic molding ( 22 ) and the head of the plug ( 51 ). 19. Plastic molding according to one of claims 1 to 18, characterized in that the plastic molding ( 22 ), in the cavity of which a shielding part ( 23 ) is located, part or all of a housing of an electronic device, for. B. an information processing unit forms. 20. Plastic molding according to claim 19, characterized in that there is an electrical connection between the shielding part ( 23 ) in the plastic molding ( 22 ) and a conductive frame ( 71 ) of the electronic device. 21. A process for producing a plastic molding, characterized by the process steps:
sandwiching a shielding part ( 23 ) between two plastic plates ( 22 a, 22 b) to form a molded part ( 34 ),
Heating the molded part ( 34 ) in order to soften the plastic plates ( 22 a, 22 b),
Introducing a compressed gas into the molded part ( 34 ), which is in a mold ( 32 ) with a recess ( 32 c) with a predetermined shape, so that a plastic molded part ( 22 ) is produced, which contains the shielding part ( 23 ) and has a hollow cross section. 22. A method for producing a plastic molding according to claim 21, characterized in that the shielding part ( 23 ) by an adhesive part ( 47 ) is attached to one of the plastic plates ( 22 a, 22 b) when the shielding part ( 23 ) sandwiched between the two Plastic plates ( 22 a, 22 b) is bordered. 23. A method for producing a plastic molding according to claim 22, characterized in that the adhesive part ( 47 ) is cured by heating the molded part ( 34 ). 24. A process for producing a plastic molding, characterized by the process steps:
Shaping molten plastic into a plate of a predetermined size with a cavity and an open end region,
Introducing a shielding part ( 23 ) from the open end area,
Introducing compressed air into the cavity in a mold ( 32 ) with a recess ( 32 c) with a certain shape, so that a plastic molded part ( 22 ) is produced which contains the shielding part ( 23 ) and has a hollow cross section. 25. A method for producing a plastic molding according to claim 21 or 24, characterized in that the shielding part ( 23 ) from the plastic molding ( 22 ) emerges as a conductive part ( 23 a) ago when the plastic molding ( 22 ) is formed with its hollow cross section , And that on the plastic molded part ( 22 ) is formed a conductive part ( 52 ) which is electrically connected to the conductive part ( 23 a). 26. A method for producing a plastic molding according to claim 25, characterized in that the electrical connection between the conductive part ( 52 ) and the conductive part ( 23 a) by driving a plug ( 51 ) into the conductive part ( 52 ) and the conductive Part ( 23 a) is made. 27. A method for producing a plastic molding according to claim 25 or 26, characterized in that a conductive connecting member ( 54 ) is used in such a way that it electrically connects the conductive member ( 52 ) and the conductive part ( 23 a), and that the plug ( 51 ) is then driven into the conductive member ( 52 ) and the conductive connecting member ( 54 ). 28. A method for producing a plastic molding according to claim 21 or 24, characterized in that in the formation of the plastic molding ( 22 ) with a hollow cross section using the shape of the recess ( 32 c) of the mold ( 32 ), the shielding part ( 23 ) so is molded so that it comes into contact with one of the opposite portions of the plastic molding ( 22 ) and a conductive member ( 52 ) is attached to that part of the plastic molding ( 22 ) which corresponds to a position where the shielding member ( 23 ) and the inner wall of the molded plastic part ( 22 ) are in contact. 29. A method for producing a plastic molding according to claim 28, characterized in that a plug ( 51 ) from the conductive member ( 52 ) in the shielding part ( 23 ) is ben ben. 30. A method for producing a plastic molding according to claim 21 or 24, characterized in that in the formation of the plastic molding ( 22 ) with a hollow cross-section using the shape of the recess ( 32 c) of the mold ( 32 ) on the other of the opposite A retaining groove ( 56 ) is formed in sections of the molded plastic part ( 22 ) and that a conductive member ( 52 ) is formed in this retaining groove ( 56 ) to establish contact between the shielding part ( 23 ) and an inner wall of one of the opposite sections of the molded plastic part ( 22 ). is used with press fit. 31. A method for producing a plastic molding according to claim 30, characterized in that after the holding groove ( 56 ) has been formed, a conductive insert ( 57 ) is introduced therein and the conductive member ( 52 ) is press-fitted into this insert ( 57 ) . 32. A method for producing a plastic molding according to claim 21 or 24, characterized in that compressed air is introduced into a first and a second space and by trimming the molded part ( 34 ) in a section in which the second space is formed, a holding groove ( 61 ) is formed so that a conductive member ( 65 ) with an interference fit is inserted in this holding groove ( 61 ) and that the first and the second space are formed using the configuration of a recess ( 32 c) of the mold ( 32 ). 33. A method for producing a plastic molding according to claim 21 or 24, characterized in that after the molding of the plastic molding ( 22 ) with a hollow cross-section, a stop fen ( 51 ) for electrical connection of the shielding part ( 23 ) and the plastic molding ( 22 ) with an interference fit is introduced into the plastic molding ( 22 ). 34. A method for producing a plastic molding according to claim 33, characterized in that a conductive member ( 52 ) is interposed when the plug ( 51 ) is used with Preßpas solution. 35. Device for producing a plastic molding, characterized by
Assembly means ( 36 ) for producing a molded part ( 34 ) by sandwiching a shielding part ( 23 ) between two plastic plates ( 22 a, 22 b),
Heating means ( 35 a, 35 b) for heating the molded part ( 34 ) for softening the plastic plates ( 22 a, 22 b),
and compression molding means ( 32 ) for introducing compressed air into the molding ( 34 ) in a molding tool ( 32 ) which has a recess ( 32 c) with a predetermined shape, so that a plastic molding ( 22 ) is formed which the shielding part ( 23rd ) contains and has a hollow cross section. 36. Device for producing a plastic molding, characterized by
Plastic supply means ( 43 ) for supplying molten plastic, which is formed into a plate with a cavity and an open end of a predetermined size,
Feeding means ( 44 ) for feeding a shield member ( 23 ) from the open end,
and molding means ( 32 ) for introducing compressed air into said cavity in a molding tool ( 32 ) having a recess ( 32 c) with a predetermined configuration, so that a plastic molding ( 22 ) is formed which contains the shielding part ( 23 ) and one has a hollow cross-section.